Cigarette filter structure



Oct, 4, 1960 H. A. LEBERT 2,954,782

CIGARETTE FILTER STRUCTURE Filed April 18, 1958 2 Sheets-Sheet 1 Oct 4 1960 H. A. LEBERT 2,954,782

CIGARETTE FILTER STRUCTURE Filed April 18, 1958 2 Sheets-Sheet 2 EU w United States Patent CIGARETTE FILTER STRUCTURE Herbert A. Lebert, Millbrae, =Calif., assignor to Mac- Farland, Aveyard & Company, Chicago, 11]., a corporation of Delaware Filed Apr. 18, 1958, Ser. No. 729,339

6 Claims. (Cl. 131-187) The present invention relates to tobacco smoking structures such as a cigarette and the like. More particularly, the present invention relates to a tar removal structure and method of manufacturing the same whereby the structure may be utilized at the end of avcigarette to form a filter-tip cigarette and which tar removal structure is pro- ,vided with a venturi passageway area so that the velocity space between the filaments for a 7 diameter filter tip can be compressed into a As" diameter rod or bundle, that is, a reduction in cross-sectional area from approximately .07 square inch to .01 square inch or the equivalent of an air passage of approximately .06 square inch or diameter. Such a large air passage is in marked contrast to the inch or less orifice used to create high velocity-impingement tar collection according to the principles of my invention as set forth in my earlier filed copending application, Serial No. 662,049, filed May 28, 1957, for Removal of Tar and Other Deleterious Substances From Tobacco Smoke.

According to the present invention a very important feature involves the concept of manufacturing a tobacco tar removal structure which may be inserted into preferably a filter tip for a cigarette although it will be understood such structure may be adapted for use in other tobacco smoking structures. The tobacco tar removal structure comprises an insert structure in each instance and is enclosed within an outer tubular sleeve which joins the tobacco tar removal structure with one end of a cigarette.

The present tobacco tar removal structure differs from conventional filter-tip cigarettes in that most of the conventional filter-tip cigarettes are comprised of a cellulose material and such material is relied upon to collect tars by virtue of the maze formed by the filaments and the circuitous path the smoke travels in passing along the length (approximately W of the filter tip.

In contrast to the above conventional filter tips, by

utilizing the present construction it is no longer necessary Patented Oct. 4, 1960 cigarettes is considerably more expensive than paper-like materials and the like.

According to the present invention, an important object is to form the critical sized smoke passage or venturi in the tortuous smoke channel area so that the venturi will operate to speed up the smoke to a terrific velocity exceeding e.g. ft. per second so that the heavy (high temperature formed) tar molecule or particles will not be able to meander their way through the tortuous smoke channel area, but will, instead, impinge against and come to rest on the paper-like barrier that confronts ,or stands in their high speed, straight line path from the venturi. The lighter weight aromatic, low temperature formed smoke particles or fractions which go to make up a safe, enjoyable smoke will change their high speed straight line path to the barrier and thereby will be deflected away from the barrier through the channel area and out through the open end of the tube.

In the past, expansion cooling of tobacco smoke has been practiced and structures developed to attain this end have required an elongated expansion chamber for the smoke to expand which structure is conventional in the art. According to the present invention, the manufacturing cost of the filter tip may be kept to a minimum since the expansion chamber is not required and the dimensions of the conventional filter tip may remain substantially unaltered despite the inclusion of the critical passage area in the filter tip. In fact, if it is desired, the over-all length of the filter tip may be reduced without interference with the tar removal operation of the filter tip. Another advantage of the present invention is that by manufacturing the tar removal structure from paper, the cost of the paper used in the tar removal structure will be reduced to approximately 50% of the cost of the cellulose used in the conventional filter tip.

If the filter tip construction is manufactured with an orifice or venturi area, for example, equivalent to an .O28".030" diameter hole, all the tars regarded harmful 1 by modern medical thinking will be deposited that is, impinged on the filter tip filaments and thereby removed from the tobacco smoke.

Accordingly an object of the present invention is to provide a new and improved filter tip construction which is highly economical.

Yet another object of the present invention is to provide a filter tip construction which lends itself to relatively inexpensive manufacture on a large production scale.

A further object of the present invention is to provide a new and improved filter tip cigarette construction of the type whereby substantially all the tars regarded harmful by modern medical thinking will be deposited within the filter tip and thereby removed from the tobacco smoke.

Other objects and features of the present invention will more fully become apparent in view of the following detailed description taken in conjunction with the accompanying drawings illustrating therein several embodiments and in which:

Figure 1 is a fragmentary cross-sectional view of a first type of filter-tip cigarette according to the principles of the present invention;

Figure 2 is a vertical sectional view taken substantially on the line 11-11 of Figure 1 looking in the direction indicated by the arrows;

' Figure 3 is a fragmentary cross-sectional view of a second type of filter-tip cigarette;

Figure 4 is a vertical sectional view taken substantially on the line IV--IV of Figure 3 looking in the direction indicated by the arrows;

Figure 5 is a vertical sectional view taken substantially indicated by the arrows; I

Figure 6 is a fragmentary cross-sectional view illustrating a third form of filter-tip cigarette;

Figure 7 is an exploded view ofan insert tar removal disk structure;

Fignlre 8 is a fragmentary cross-sectional view illustrating a fourth form of a filter tip cigarette withthe tar removal insert structure of Figure 7 shown in section herein;

Figure 9 is an exploded view of a tobacco tar removal disk-structure;

Figure 10 is a fragmentary cross-sectional view of a fifth type of filter tip cigarette with the tar removal insert structure of Figure 9 shown in assembly therewith;

'Figure 11 is an exploded view of a tobacco tar removal disk structure; and I Figure 12 is a fragmentary cross-sectional view of a six type of filter-tip cigarette with the tobacco tar removal structure of Figure 11 shown in section therein.

The reference numeral 10 designates generally a filtertype cigarette including a tubular sleeve 11', a tobacco tar removal structure 12, and a cigarette 13. As is apparent in Figure 1, both the tobacco tar removal structure 12 as well as one end of the cigarette are telescoped within the tubular sleeve 11 so as to be secured in unitary assembly together.

The tar removal structure 12 may be made from any suitable material such as papier-mache, plastic, or any other suitable material. In the present instance the tar removal structure 12 is comprised of a substantially solid cylindrical block of material. At 12a and 12b there are provided reduced annular circular surface areas which reduced surface areas are disposed at the axially op- .posite ends of the structure 12. Disposed between the reduced surface areas is an annular circular sleeve engaging shoulder area 12c. Annular axially facing juncture shoulders 12d and 12s are provided at the intersection of the surface 120 with the reduced annular surfaces 12a and 12b.

It will be noted in Figure 1 that when the sleeve 11, the tar removal structure 12 and the cigarette 13 are in assembly together a smoke passageway is defined as designated generally at 14. The passageway 14 includes a smoke collection chamber area 14a which is defined by the radially facing annular surface 12b as well as the axially facing annular surface 12e in combination with butt end 13a of the cigarette and inside circular surface 11a of the sleeve.

Extending diagonally across the tobacco tar removal structure is a reduced cross-sectional venturi passageway area or venturi indicated generally at 15 which communicates at one end with the smoke collection chamber 14a and has an impingement barrier or impingement barrier area 1-6 disposed in confronting relation to the discharge end or downstream end of the passageway 15. It will be noted that the surfaces 12a and 12d along with the inside sleeve surface 11a define an annular tar sump as indicated generally at 14b in which tars T may be collected after they have collided with the inside surface 11a of the tubular sleeve at the impingement area 16.

The smoke collection chamber 14a preferably has a reduced thickness in the order of 010-015 so that particles of tobacco may not be readily drawn into the smoke collection chamber. After the filter-tip cigarette 10 has been ignited, by applying a suction force to the open end of the sleeve 11, smoke may be drawn into the collection chamber 14a and then through the critical sized orifice or venturi passageway area 15 whereupon tarsT may be impinged against the impingement barrier 16 with the chamber 14b providing a tar collection sump for the collection of the heavy tars removed from the tobacco smoke. The tobacco smoke after it has struck the impingement barrier 16 will be deflected axially or longitudinally of the venturipassagewaywls toward the open end of the sleeve 11.

In the past, the problem presented has been one of providing sufficient smoke flow to satisfy the smoker while at the same time removing the deleterious tars, etc. 'In the structure of the present invention, this problem is overcome by providing the venturi orifice or passageway 15 which greatly increases the velocity of smoke stream passing through the filter tip so that when the stream strikes the barrier, the tar is lodged and collected upon the peripheral surface of the paper or other suitable mate rial and the resulting purified smoke alters its course through the structure and passes on to the smoker through the downstream end of the filter tip. By referring to the removal of tars, the term tars should be regarded as embracing tars, resins, and other harmful substances. While there will be variations in the size of the orifice, depending upon the character of the smoke, the density of the cigarette masspetc. in general effective results are obtained when the orifice diameter is from..025 to .038 (square inch areas of .0005 to .001). Very satisfactory results have been obtained where the orifice diameter is .028 inch to .032 inch (.0006 to .0008 square inch).

As a preferred example, I have employed effectively an orifice having a diameter of .030 (.0007 square inch), which gives excellent tar removal and ease of drawing.

The critical orifice size is correlated with the impingement barrierwhich islocatcd as close as possible to the orifice or venturi outlet consistent with the free flowing of the collected tars; i.e.', without impairing the flowing of the tar away from the point of impingement. In prac tice, I have found that a satisfactory range is a distance of .005 to .030". In the specific example referred to, the impingement barrier 16 is preferablyspaced from the orifice or venturi 15 by A of an inch (.015"), or approximately one-half the orifice diameter.

The operation resulting from the structure shown herein is in contrast to the operation of cooling devices heretofore employed with cigarettes or cigarette holders. Such cooling devices bring about a peripheral cooling of the smoke but allow substantial core portions of the tars to pass onto, the smoker. In my structure, the entire crosssection of the smoke stream is subject to the action of the impingement area 16 so that the tars T and other harmful particles are removed by the foregoing high velocity impingement action upon the barrier 16.

'The slight spacing between the outlet of the orifice and the barrier enables the smoke stream to reach the barrier with substantially undiminished speed, while at the same time enabling the purified smoke to change direction, whereas tar fractions, by reason of their high inertia, can

not change direction and therefore deposit on the first surwill not soak through the sleeve and come into contact with the lips of the smoker. The tars will however be visible from the open end of the sleeve;

The reference numeral in Figures 3-5 indicates a modified form of a filter-type cigarette which includes a tubular'sleeve 111, a tobacco tar removal structure 112 and a cigarette 113.

The tobacco tar removal structure 112 may be com.- prised of the same material as the tobacco structure 12 previously described. The tobacco tar removal structure 112 differs from the corresponding structure 12 in Figures 1 and 2 in that it is adapted to extend substantially the full length of the tubular sleeve 111. 3 The tobacco tar removal structure further differs from the corresponding structure shown in the first form'in that it is of a hollow type construction. When the tobacco tar removal structure 112 and the cigarette 113 are telescoped Within the sleeve 1-11 they are abutted against one another in unitary assembly with the sleeve. At this time annular circular surfaces 112:: and 1121) are disposed in radially spaced relation to the side surface 111a of the tubular sleeve whilecircular annular enlarged surface 112c'is frictionally engaged with the inside surface 111a of the sleeve.

The filter-type cigarette has extending therethrough a smoke passageway designated generally at 114. This preciated that these annular surfaces cooperate with the side surface 11d of the sleeve to define the passageway areas 114a and 114k. The distance between the sleeve surface 111a and the tobacco tar removal structure surface 112b is preferably about .0l0-.0l5" so'as to preclude any tendency of tobacco particles from being drawn into the smoke collection chamber 11% and thereby block the free flow of smoke through the passageway 114. The passageway 114 also includes reduced cross-sectional venturi passageway areas or venturis or orifices 115 and 115a. The venturi passageway area 115 extends in a generally radially inwardly axially forwardly direction toward the end of the cigarette to be ignited and links the annular smoke collection chamber area 114a with the smoke collection chamber 114:: disposed internally of the structure 112. The tobacco tar removal structure has an internal surface area which confronts the downstream end of the venturi passageway 1:15 and which is spaced slightly therefrom and comprises an impingement barrier or impingement barrier area designated generally at 116.

The venturi passageway area 115a extends generally radially outwardly and axially toward the end of the cigarette to be ignited and links the smoke collection chamber area 1140 with the tobacco tar collection area or smoke discharge area 114b.

Upon a suction force being applied to the downstream end of the sleeve 111 of the filter-type cigarette 110 smoke is drawn into the smoke collection chamber area 114a whereupon it passes through the venturi passageway 115 in a manner whereby the velocity of the smoke is greatly accelerated. As the smoke discharges from the venturi passageway 115 it collides with the impingement barrier 1 16 and tars are deposited thereon with the smoke being deflected into the smoke collection chamber area 1140 whereupon the smoke passes through the second venturi passageway area 115a.- The smoke then discharges at high velocity from the downstream end of the venturi passageway area 115a and collides with the impingement barrier area 116a which is in this instance defined by the insidesurface of the tubular sleeve 111. After the smoke collides with the barrier tars are deposited thereon and the smoke is deflected and allowed to pass out of the sleeve 111 and into the mouth of smoker. It will be understood that,,the construction and configuration of the venturi passageways 115 and 115a is substantially the same as the venturi passageway previously described and designated in Figures 1 and 2 at 15.

It will be appreciated that the modified filter tip cigarette 110 is adapted to remove more of the tars contained in the tobacco smoke than the filter-type cigarette since a double venturi passageway area arrangement is. provided.

Shown in Figure 6 is still a third form of a filter-type cigarette designated generally at 210. The filter-type 'cigarette 210 includes a tubular sleeve 211, a tobacco tar removal structure 212, and a cigarette 213 which are assembled together in the same manner previously described in connection with Figure 3. The tobacco tar removal structure cooperates with the sleeve as well as the cigarette and has extending longitudinally therethrough a smoke passageway 214 including a smoke collection area 214a and a central smoke discharge area 214a. The area 2140 comprises a recessed areaof the tar removal structure 212.

Whenthe tar removal structure 212 is disposed in unitary assembly within the sleeve 211 its upstream end abuts against the cigarette end surface 213. The structure 212 is provided with an annular circular reduced surface area 212b which is radially spaced from the inside surface 211a of the sleeve. The structure 212 is also provided with an enlarged annular circular surface area 2120 which is frictionally engaged with the inside surface area 211a. At the junction of the surfaces 212b and 2120 is provided an annular axially facing surface 2140. It should be noted that the surfaces 213a, 212b, 212e, and 211a define the annular smoke collection chamber area 214a.

Disposed in the tobacco tar removal structure 212 is a reduced cross-sectional venturi passageway area or orifice or venturi 215 which extends generally radially inwardly axially forwardly toward the end of the cigarette which is to be ignited. This passageway area 215 links the smoke collection chamber area 214a with the smoke discharge area 2140 in a manner whereby smoke may be drawn at high velocity through the venturi passageway area 215 so that it may be collided against an impingement barrier or impingement barrier area 216 on the structure 212 so that tars T may be removed from the smoke in the same manner as previously described. After the tars have been removed as a consequence of the high velocity collision of the smoke against the barrier 216 the smoke is deflected and drawn through the discharge area 2140 defined centrally of the tobacco tar removal structure 212. The venturi passageway and impingement barrier relationship is the same as previously was described in connection with the other forms of the present invention.

Shown in Figures 8, 10 and 12 are three additional modified filter-type cigarettes designated generally at 25, 125, and 225. Each of these cigarettes includes a tubular sleeve designated generally at 26, 1-26, and 226, a tobacco tar removal structure indicated at 28, 128, and 228, and a cigarette indicated at 29, 129, and 229. In all three forms it will be noted that one end of the cigarette as Well as the tobacco tar removal structure are telescoped inside of the tubular sleeve and sustained together in unitary relationship therewith.

The tobacco tar removal structure 28 is comprised of five relatively rflat circular built-up disks indicated at 28a, 28b, 28c, 28d and 28s. The disks 28a and 2812 are of an identical construction as are the disks 28b and 28d. The disks 28a and 28e each have a fiat beveled edge indicated at 30 and 30a. The disks 28b and 28d have key hole type slot areas designated generally at 31 and 31a. The slot areas 31 and 31a are comprised of circular recessed areas 32, 32a and radially extending reduced crosssectional venturi passage areas or orifices or venturis 33, 33a. The recessed areas 32, 32a are centrally located on the disks 28b and 28d and the venturi passageways 32, 32a are connected at the radially inner ends thereof with the recessed areas 32, 32a and with the venturi passageways extending radially outwardly to the outer marginal edge areas of the disks.

The disk 28c has a central recessed area 34' which is centrally located and adapted to be disposed in axial alignment between the recessed areas 32 and 32a. The recessed areas 34, 32, and 32a are all circular and have equal diameters.

When the tobacco tar removal structures 28, 128, and 228 are telescoped inside of the tubular sleeves radially outer peripheral edge areas 28 1287'", and 228 are adapted to be frictionally engaged with the inside surfaces of the sleeves. The disks may be glued or secured in any suitable manner such as by a suitable paper glue.

The disks of the tar removal structure 28 are arranged in a predetermined manner whereby the beveled edges 30 and 30a as well as the venturi passageway areas 33 and 33a are not only disposed in axially spaced relation but the disks are rotated relative to one another;

This disc 28b is possessed of an impingement barrier or impingement barrier area 34 which is spaced'radially inwardly of the radially inner end of the venturi passageway area 33. The sleeve 26 has aninside surface area indicated generally at 26a with the inside surface area 26a disposed at the radially outer end'of the venturipassage-- way area 33a comprising a second impingement barrier indicated at 34a.

Upon the application of'a suction force to the open end of the sleeve 26 smoke may be drawn through a smoke passageway designated generally at 35 in the filter-type cigarette. The passageway 35 is defined between the beveled edge 30 and the inside surface area 26a opposite the beveled edge 30, the venturi passageway area 33, the recessed'areas 32, 34 and 32a, the venturi passageway 33a and between the beveled edge 30a and the inside surface area 26a opposite the beveled edge 30a. Hence when smoke is drawn through the cigarette-type structure 25 the velocity of the smoke will be greatly accelerated as the smoke passes through the venturi passageways33 and 33a with the result that tobacco tars will be impinged upon the impingement barriers 34, 34a whereupon the smoke will eventually flow into the mouth of the smoker in a substantially cleansed condition.

The tobacco tar filter structure 128 is comprised of circular disks 128a, 128b, 1280, 12801 and 128e. The structure 128 is somewhat similar to the tobacco tar filter structure 28 especially since the disks 128a and 128a are identical in construction as is also the case with respect to the disks 1281a and 128d.

The disks have a series of circular recessed areas designated at 130a, 130b, 1300, 130d, 1302, 130 and 130g. As apparent in Figure 9 the disks 128b and 128d are each possessed of two of the recessed areas. The recessed areas 13% and 1300 on the disk 12% are linked together by a reduced cross-sectional venturi passageway area or orifice or venturi 131. The recessed areas 13% and 130i on the disk 128d are linked togetherby a second recessed area designated generally at 131a. Thus it will be appreciated that the filter-type cigarette 125 is possessed with a passageway area 132 which extends longitudinally through the cigarette 129, the tobacco tar removal structure 128 and the sleeve 12 6. When a suction force is applied to the open end of'the sleeve 126 smoke is drawn. from the ignited end of the cigarette 129 through the recessed areas 130a, 13012 whereupon the smoke is accelerated as it passes through the venturi passageway area 131 and into the recessed area 130e, 130a, and 130s. As the smoke passes through the recessed area 130e it is again accelerated as it flows through the venturi passageway area 131a into the recessed areas 130 and 130g and then axially into the mouth of the smoker. It should be noted that impinge- Inent barriers or impingement barrier areas 133 and 133a are disposed in radially spaced relation to the downstream end of the venturi passageway areas 131 and 131a so that the tars may be removed from the smoke as the smoke passes through the tar removal structure in the same manner as previously described.

The tobacco tar removal structure 228 shown in Figures 11 and 12 diifers from that shown in Figures ".7, 8, 9 and in that it is only comprised of three plates 228a, 22812, and 228C. The plates aforementioned are possessed of a series of circular recessed areas 230a, 230b, 230a and 2300! with each of the recessed areas be- :ing circular and having the same diameter. The plate .2281: is provided with two of the recessed areas 23012 .and 230s and they are joined together by a reduced cross-sectional venturi passageway area or orifice or venturi 231.

The filter-type cigarette 225 also has a smoke passage way 232 extending longitudinally therethrough. When a suction force is applied to the open end of the sleeve 226 smoke is drawn from the ignited end of the cigarette through the venturi passageway 231 into the recessed varea 230a and axially out through the recessed area 230d intotthe mouth of the smoker. The recessed area 230c has an impingement barrier or impingement barrier area 233 disposed radially outwardly of the downstream end of the venturi passageway 231. I i

The disk type tobacco tar removal structures may be manufactured from any suitable materials such as thin paper, plastic, and the like and the dimensional relationships of the venturi passageway areas as well as the spacing between the venturi passageway areas and the impingement barriers are the same as previously described. i

In view of the foregoing description it will now be appreciated how a new and improved type of filter-type cigarette may be' manufactured of a type which will very substantially reduce the cost of the filter tip structure while at the same time enabling a substantially greater amount of tar to-be removed from the smoke to be inhaled by the smoker. By removing an increased amount of the harmful tars from the smoke harmful effects from smoking may be very substantially diminished.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. A cigarette filter assembly including a mouthpiece sleeve adapted to receive the butt end of a cigarette within a forward socket end portion of the sleeve and with the tobacco of the cigarette exposed at the sleeveencompassed butt end of the cigarette, a filter structure of the. same outside diameter as the inside diameter of the sleeve and secured within the sleeve, said filter structure having a solid forward face impervious to smoke and disposed to oppose the exposed tobacco of the butt end of the cigarette and thereby substantially blocking rearward escape of tobacco particles, a smoke-receiving passageway in said filter structure opening through said forward face and extending rearwardly therefrom a limited distance and thenbeing blocked by a solid portion of the filter structure, said passageway being of a cross-sectional area to afford free movement of smoke 'therethrough from said butt end but to avoid being clogged all of the accelerated smoke must strike the barrier and deposit'tars thereon, and a further passageway in said filter structure leading from said barrierand extending rearwardly and enabling movement of the smoke laterally from said barrier and out through the rear portion of the mouthpiece sleeve.

2. A cigarette filter assembly as defined in claim 1, wherein said filter structure is reversible end-for-end and has in addition to said solid'forWaId face a solid rear face and said further passageway is capable of being the smoke-receiving passageway upon reversalof the filter structure relative to the mouthpiece sleeve and said sleeve socket.

3; A cigarette-filter assembly as defined 1n clarm 1, wherein said filter structure comprises a solid-cylindrical body, said smoke-receiving passageway is an annular groove in the perimeter of the body at said forward face, said further passageway comprising'a peripheral groove in the rear end portion of the body and opening rear: wardly from the rear face of the body, and said venturi orifice extends from the rear'end ofsaid smoke-receivmg through the recessfid a eas 2310a, 230b, and then 7 5 passageway grooveand hasitsdownstream end opening through the forward end portion of said further passageway groove and the mouthpiece sleeve portion surrounding said further passageway groove providing said impingement barrier.

4. A cigarette filter assembly as defined in claim 1, wherein said filter structure comprises a cylindrical body having a circumferential groove about its forward end portion opening forwardly through said forward face and extending rearwardly to a substantial length, said body being hollow and having a rearwardly facing surface spaced rearwardly from said forward face but also spaced forwardly from the rear end of said groove, and said venturi orifice extending diagonally inwardly and forwardly and discharging against said rearwardly facing face, said hollow interior of said body providing a part of said further passageway and having a discharge opening in the rear portion of the body.

5. A cigarette filter assembly as defined in claim 4, wherein said filter body has a solid rear end closure and a venturi orifice leads from the rear end portion of the hollow interior and discharges against a slightly spaced 10 portion of the sleeve serving as an impingement barrier, whereby smoke drawn through the filter assembly is doubly cleansed of tars.

6. A cigarette filter assembly as defined in claim 1, wherein said filter structure comprises a laminated series of disks including a forward disk providing said forward face and. a rearward disk providing said venturi orifice and said impingement barrier.

References Cited in the file of this patent UNITED STATES PATENTS 1,594,606 Clivio Aug. 3, 1926 2,105,539 Lang June 18, 1938 2,202,288 Heron May 28, 1940 2,511,898 Brothers June 20, 1950 2,586,195 Wood Feb. 19, 1952 2,764,513 Brothers Sept. 25, 1956 FOREIGN PATENTS 414,147 France June 11, 1910 760,772

Great Britain Nov. 7, 1956 

